vim-patch:8.1.2212: cannot see the selection type in :reg output

Problem:    Cannot see the selection type in :reg output. (Ayberk Aydın)
Solution:   Add c/l/b. (Christian Brabandt, closes vim/vim#5110, closes vim/vim#4546)
https://github.com/vim/vim/commit/3691f1ee72b68a47e6dcc75927bfa46565cf3614

Patch v8.1.0999 is not ported so ":registers" does not omit register 1.

4 files changed, 53 insertions, 39 deletions

diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index 5c67359002..f3ed086933 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -954,9 +954,13 @@ inside of strings can change!  Also see 'softtabstop' option. >
 			delete and yank) ({.%#:} only work with put).
 
 							*:reg* *:registers*
-:reg[isters]		Display the contents of all numbered and named
-			registers.  If a register is written to for |:redir|
-			it will not be listed.
+:reg[isters]		Display the type and contents of all numbered and
+			named registers.  If a register is written to for
+			|:redir| it will not be listed.
+			Type can be one of:
+			"c"	for |characterwise| text
+			"l"	for |linewise| text
+			"b"	for |blockwise-visual| text
 
 
 :reg[isters] {arg}	Display the contents of the numbered and named
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 8fddb1b561..052b07ed44 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -3554,15 +3554,21 @@ void ex_display(exarg_T *eap)
   int name;
   char_u *arg = eap->arg;
   int clen;
+  char_u type[2];
 
   if (arg != NULL && *arg == NUL)
     arg = NULL;
   int attr = HL_ATTR(HLF_8);
 
-  /* Highlight title */
-  MSG_PUTS_TITLE(_("\n--- Registers ---"));
+  // Highlight title
+  msg_puts_title(_("\nType Name Content"));
   for (int i = -1; i < NUM_REGISTERS && !got_int; i++) {
     name = get_register_name(i);
+    switch (get_reg_type(name, NULL)) {
+      case kMTLineWise: type[0] = 'l'; break;
+      case kMTCharWise: type[0] = 'c'; break;
+      default: type[0] = 'b'; break;
+    }
 
     if (arg != NULL && vim_strchr(arg, name) == NULL) {
       continue;             /* did not ask for this register */
@@ -3587,11 +3593,14 @@ void ex_display(exarg_T *eap)
 
     if (yb->y_array != NULL) {
       msg_putchar('\n');
+      msg_puts("  ");
+      msg_putchar(type[0]);
+      msg_puts("  ");
       msg_putchar('"');
       msg_putchar(name);
       MSG_PUTS("   ");
 
-      int n = Columns - 6;
+      int n = Columns - 11;
       for (size_t j = 0; j < yb->y_size && n > 1; j++) {
         if (j) {
           MSG_PUTS_ATTR("^J", attr);
@@ -3616,8 +3625,8 @@ void ex_display(exarg_T *eap)
    */
   if ((p = get_last_insert()) != NULL
       && (arg == NULL || vim_strchr(arg, '.') != NULL) && !got_int) {
-    MSG_PUTS("\n\".   ");
-    dis_msg(p, TRUE);
+    msg_puts("\n  c  \".   ");
+    dis_msg(p, true);
   }
 
   /*
@@ -3625,8 +3634,8 @@ void ex_display(exarg_T *eap)
    */
   if (last_cmdline != NULL && (arg == NULL || vim_strchr(arg, ':') != NULL)
       && !got_int) {
-    MSG_PUTS("\n\":   ");
-    dis_msg(last_cmdline, FALSE);
+    msg_puts("\n  c  \":   ");
+    dis_msg(last_cmdline, false);
   }
 
   /*
@@ -3634,8 +3643,8 @@ void ex_display(exarg_T *eap)
    */
   if (curbuf->b_fname != NULL
       && (arg == NULL || vim_strchr(arg, '%') != NULL) && !got_int) {
-    MSG_PUTS("\n\"%   ");
-    dis_msg(curbuf->b_fname, FALSE);
+    msg_puts("\n  c  \"%   ");
+    dis_msg(curbuf->b_fname, false);
   }
 
   /*
@@ -3646,8 +3655,8 @@ void ex_display(exarg_T *eap)
     linenr_T dummy;
 
     if (buflist_name_nr(0, &fname, &dummy) != FAIL) {
-      MSG_PUTS("\n\"#   ");
-      dis_msg(fname, FALSE);
+      msg_puts("\n  c  \"#   ");
+      dis_msg(fname, false);
     }
   }
 
@@ -3656,8 +3665,8 @@ void ex_display(exarg_T *eap)
    */
   if (last_search_pat() != NULL
       && (arg == NULL || vim_strchr(arg, '/') != NULL) && !got_int) {
-    MSG_PUTS("\n\"/   ");
-    dis_msg(last_search_pat(), FALSE);
+    msg_puts("\n  c  \"/   ");
+    dis_msg(last_search_pat(), false);
   }
 
   /*
@@ -3665,8 +3674,8 @@ void ex_display(exarg_T *eap)
    */
   if (expr_line != NULL && (arg == NULL || vim_strchr(arg, '=') != NULL)
       && !got_int) {
-    MSG_PUTS("\n\"=   ");
-    dis_msg(expr_line, FALSE);
+    msg_puts("\n  c  \"=   ");
+    dis_msg(expr_line, false);
   }
 }
 
@@ -3676,9 +3685,10 @@ void ex_display(exarg_T *eap)
  */
 static void
 dis_msg(
-    char_u *p,
-    int skip_esc                       /* if TRUE, ignore trailing ESC */
+    const char_u *p,
+    bool skip_esc     // if true, ignore trailing ESC
 )
+  FUNC_ATTR_NONNULL_ALL
 {
   int n;
   int l;
diff --git a/src/nvim/testdir/test_registers.vim b/src/nvim/testdir/test_registers.vim
index 2f72b6a4c0..8a90f9b251 100644
--- a/src/nvim/testdir/test_registers.vim
+++ b/src/nvim/testdir/test_registers.vim
@@ -52,27 +52,27 @@ func Test_display_registers()
     let b = execute('registers')
 
     call assert_equal(a, b)
-    call assert_match('^\n--- Registers ---\n'
-          \ .         '""   a\n'
-          \ .         '"0   ba\n'
-          \ .         '"1   b\n'
-          \ .         '"a   b\n'
+    call assert_match('^\nType Name Content\n'
+          \ .         '  c  ""   a\n'
+          \ .         '  c  "0   ba\n'
+          \ .         '  c  "1   b\n'
+          \ .         '  c  "a   b\n'
           \ .         '.*'
-          \ .         '"-   a\n'
+          \ .         '  c  "-   a\n'
           \ .         '.*'
-          \ .         '":   ls\n'
-          \ .         '"%   file2\n'
-          \ .         '"#   file1\n'
-          \ .         '"/   bar\n'
-          \ .         '"=   2\*4', a)
+          \ .         '  c  ":   ls\n'
+          \ .         '  c  "%   file2\n'
+          \ .         '  c  "#   file1\n'
+          \ .         '  c  "/   bar\n'
+          \ .         '  c  "=   2\*4', a)
 
     let a = execute('registers a')
-    call assert_match('^\n--- Registers ---\n'
-          \ .         '"a   b', a)
+    call assert_match('^\nType Name Content\n'
+          \ .         '  c  "a   b', a)
 
     let a = execute('registers :')
-    call assert_match('^\n--- Registers ---\n'
-          \ .         '":   ls', a)
+    call assert_match('^\nType Name Content\n'
+          \ .         '  c  ":   ls', a)
 
     bwipe!
 endfunc
diff --git a/test/functional/provider/clipboard_spec.lua b/test/functional/provider/clipboard_spec.lua
index 1431054494..2c681eb9d8 100644
--- a/test/functional/provider/clipboard_spec.lua
+++ b/test/functional/provider/clipboard_spec.lua
@@ -605,10 +605,10 @@ describe('clipboard (with fake clipboard.vim)', function()
       {0:~                                                           }|
       {4:                                                            }|
       :registers                                                  |
-      {1:--- Registers ---}                                           |
-      "*   some{2:^J}star data{2:^J}                                      |
-      "+   such{2:^J}plus{2:^J}stuff                                      |
-      ":   let g:test_clip['+'] = ['such', 'plus', 'stuff']       |
+      {1:Type Name Content}                                           |
+        l  "*   some{2:^J}star data{2:^J}                                 |
+        c  "+   such{2:^J}plus{2:^J}stuff                                 |
+        c  ":   let g:test_clip['+'] = ['such', 'plus', 'stuff']  |
       {3:Press ENTER or type command to continue}^                     |
     ]], {
       [0] = {bold = true, foreground = Screen.colors.Blue},